Method for treating potatoes



Patented May 11, 1948 METHOD FOR TREATING POTATOES Margaret Wilson, Raleigh, N, O.

No Drawing. Application December 27, 1944: Serial N0. 570,488

Claims. (01; 99-156) This invention relates to a method of treating and preparing potatoes and similar vegetables for market and for other purposes.

The bright attractive surface which freshlydug potatoes have, soon changes to a dark, dull appearence which, while it does not affect their quality as a food, detracts from their attractiveness and saleability.

It is an object of my invention to provide a method whereby freshly-dug and washed potatoes and like tubers, may be treated in a rapid and efilcient manner to partially soften, decompose, or gelatinize the cells comprising the phellem or outer portion of the periderm layer of the skin.

Another object of my invention is to provide a method for treating the outer surfaces of tubers, particularly potatoes, to produce a natural bright glazed and attractive surface that isv durable, long lasting, and one that will enhance their saleability and increase their use as an article of diet.

Another object is to provide a method of treating potatoes, that will reduce the present large losses due to mold and rot.

A still further object is to provide a. method of treating potatoes that have lost their lustre because of the aforesaid rapid evaporation of skin moisture, whereby the original bloom and lustre may be restored.

Other objects and advantages will become apparent as the description proceeds.

It has heretofore been proposed to employ relatively dilute solution of the hypochlorite of an alkali-earth metal, such as sodium, in the treatment of fruits and vegetables. For example, in the patent to Slater, 1,842,696, the use of a 0.1% to 0.5% solution of sodium hypochlorite is mentioned, while in Wilson, 2,348,946, a 2% to 6% solution of the same chemical is mentioned. In each case, the solution is relatively dilute and the time element is, quite obviously, unimportant,

since no time of action is mentioned. Furthermore, the sole purpose of the solution in all prior art with which I am familiar, is as a'sterilizing agent to kill bacteria, molds and micro-organisms causing decay, and to remove molds.

My invention efiects all of the results of the prior art but it goes much further in providing a method that causes an actual change in the cellular structure of the potato skin, whereby the aforementioned results are attained in a new and highly eflicient manner.

By extensive investigation and research I have found that the use of a much more concentrated 2 solution of a hypochlorite of an alkali-earth metal, coupled with a predetermined time of application, produces results that are far more effective than could be assumed or predicted merely on the effects of the more dilute and weaker solutions suggested by the prior art. For example, I found that a solution of sodium hypochlorite of not less than 8% concentration, acts to decompose or break down the larger outer cells of the periderm of the skin of the potato. While a solution of this or greater concentration will penetrate rapidly to the edible portions of the potato and render such portions disagreeable to the taste, I have found that by using a relatively concentrated solution, applied for a short time only, and then rapidly washing and drying the tubers, a surface is imparted that retains for a long time the bright, shiny or glazed appearance of newly-dug and washed potatoes.

In carrying my method into practice the freshly-dug potatoes are passed through an atomizing spray of the solution used and which, as aforesaid, may be an 8% solution of sodium hypochlorite. This step may be conveniently carried out while the tubers are being advanced to a scrubber washer. However the solution is applied, it must effectively cover the entire surface of the potatoes and, as the time element is very important, he so applied that all the surface of each potato is substantially instantaneously covered. I have discovered that a period of ten to twelve seconds is the proper time for the solution toact. Therefore, the treating apparatus may be'convem'ently arranged so that the aforesaid time elapses between the time each potato is covered by the hypochlorite and the time it passes into the washer.

The aforesaid solution of a concentration substantially as identified, when allowed to act for 10 to 12 seconds, decomposes or breaks down the outer layers of cells of the phellem and so softens it that not only may several of the outer layers of cells be removed by the mechanical action of the washer, but also the immediately underlying layers of cells are given a gelatinized condition that makes it possible to form a film or more compact surface that retains the moisture through strong sprays of water that immediately remove all traces of the solution. Thereafter they are mechanically scrubbed, as by revolving brushes or other mechanical devices, to thereby removethe coarse gelatinized outer layers of into the skin to a gresies pen tratio J the drier.

or the outside air is low, the "drying temperature ther to reduce thesize .ofthose outer-@8 5. that remain after the'tubers pass tolth'e drienj. Stated toes iand one that is'quickly carried out because in another way, the sughuyseieunizessurrae of the potatoes, remaining ones removalgof lthe' outer layers of cells. ct the poresr the skin ccllsaswell as-. unsightlyf blemishes. while the shorttime betwee tion of the solution-and iitsfremovaL-jo sfnot.

permit. penetration into. thefl. I; desire to point out ifltlijefs'olvent is; tact with the potato long enoughjo outer layer ofphellem that', washing and brushinsdithe'potat for purposes of human consumption-3because ;the' solvent. will jobjectionable and odor to the edible, portions $0.! the opini ns the cell structure 'offthe' will actually bei made more porous; "ofl the 'e xcessive; number oi. j 1 I cell Iayers,removed.-} nc'onoentratedg-solvent-will; be absorbed;;very quickL v-- and it wa's 'for this". reason that its deemedlimpracticalg if not impossible, by inventors :andinvestig'ators in the m I: a. dilute solvent 'be-absorbed-less quickly, but a dilutesolvent evenfbylon'g con tact, has-little or .no gelatiniaing-geffeot on the skin, iwhilethe active ingredient of feven a very. dilute solution, absorbed 'into' the. P tato and impart. an objectionable taste and odor thereto;- an", appreciable time before even the gelatinizing eiiect has been. pro.- duced. That is why the combination. of the con-- cen'trated solution; coupled with a predetermined time. di tion.- iscriticaiandgives a new and wholly imited-result.

Asfsoon as the potatoes, are washed and all traces iofthejhypochlorite solution have been removedor-washed awayfiheootatoes are passed to a dryer wh'ereithey..-are.sublected to blasts of heatedlair of [such temperature and velocity that the i iui i'ace"{ i'noifsture H porated and the temperature ne; humidity. f the temperature or 110* 'to 115 general'rule.-. it impractical to attempt .to regulate the humidity the ambient air drawn into Hence, when the relative humidity.

can be correspondinglyreduced while, when said humidity is high, the temperature of the, drying air should be raisedto. effect the desired rapid rate of evaporation;

After. thepotatosare thoroughly dried, they when potatoes must be sorted by hand to sepa-- andlfdeoen ds somesuit, I have provided a method that is simple, relativelyinexpensive, highly effective in improving and keeping qualities of pota- Q the necessarily limited time during which the solvefit ispermitted to act.

e21 have described the invention as applied bi centrations. Also concentrations iicii ig the time of contact. In view of of the time I have mentioned,name

is 'bviously necessary .to usegreatcare in get satisfactory time for greater concontaq. should vary inversely as the concentraalso the solution.

:licncejl'donot 'wish to be limited by the pre ."'-ciseinunierical values identified in the foregoing specification, although they are the values now preferred by'me On the contrary, I wish to embraceinmy invention all such modifications and i-variations as fall within the scope of the sube 'joined 8ims.-' r

2 .-Having-now described my invention, what I new and desire to secure by Letters W 1 Patentis:

1': Themethod of treating tubers, comprising,

applying a solution of a hypochlorite of an alkaliearthmetal of -notless than 8% nor more than 12% concentration, and completely removing said ution from'the tubers to 12 seconds after its 40. application. I

I 2. In amethod of treating potatoeathe steps comprising, instantaneously covering the potatoes with a solution of sodium hypochlorite of not less than 8% nor more than 12 concentration, 5 for a period of 10 to 12 seconds, instantaneously removing said solution at the end or said period by. the. application of water, and quickly drying the potatoes in'strong blasts of heated air.

'3. The method of preparing tubers, to retain an a bright semi-glossy appearance and to resist mold and rot, comprising, instantaneously covering said tubers with an atomized spray of a solution of sodium hypochiorite of 8% to 12% concentration, allowing said solution to act fora period-of 10 to 12 seconds, thereafter completely removing said solution with strong sprays of water, mechanically removing a number of the outer layers of the periderm softened by said solution, and immediately evaporating all sur- 760 face moisture of said tubers. f

4. The method of treating potatoes comprising, bringing said potatoes into surface contact witha solution of sodium hypochlorite of a concentration of not less than 8% and not greater than 12%, washing said potatoesto quickly and completely remove said solution at the end of a period or 10 to 12 seconds after contact, mechanically scrubbing said potatoes to remove anumber or the outer layers .of skin cells softened by said' solutionand to reduce the cell size of the outer of 5. A method of treati Potatoes to impart obviously useful in connection;

egetables having a skin or outer covering of holly similar cell structure. Furthermore,

have mentioned a solution of sodiumhyteofnbout 8% concentration, the hypo:

tes 'of 'like alkali metals may be usedin 'e r than-8% may be used by correspondly gto lz seconds'with an 8% concentration,

nsfup to 12%. Ingeneiahthe time'i'oi 2,441,2305 V m l 5 rial 6 ereto g lasting 3 ossy surface, comp ng, applying to said potatoes an 8% to 12%solutlon 0! REFERENCES CITED m hmcmome. permitting said mu t The following references are of record in the act for a, period of 10 to 12 seconds to :eiatinize. file i D :10 outer layers of skin cells. quickly removing m STATES grm 'rs ssh! solution by washing at the end of said perind. scrubbing said potatoes to remove a number Number Name Date a; m gelltinized layers of skin cells and to glaze 1.843.595 ale outer'layers of the undcrlyins skin cells. and I fig ggggg "9 213741210 32 m :::-'m. 24 ,'1945 moms-r wn son 

